


Thin Walls

by hufflecas, shipeverythingspn (orphan_account)



Category: Supernatural
Genre: Alternate Universe, Blow Jobs, Intercrural Sex, M/M, PWP, Shower Sex
Language: English
Status: Completed
Published: 2014-01-30
Updated: 2014-01-30
Packaged: 2018-01-10 13:53:59
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,156
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1160462
Author URL: https://archiveofourown.org/users/hufflecas/pseuds/hufflecas, https://archiveofourown.org/users/orphan_account/pseuds/shipeverythingspn
Summary: <blockquote class="userstuff">
              <p>Sam's been secretly pining after his brother's best friend.  Cas stays over and Sam just can't take it any more.</p>
            </blockquote>





	Thin Walls

**Author's Note:**

> [hufflecas](http://hufflecas.tumblr.com) says: After 9x11 there were Sastiel feels. This is entirely Gabriel's ([shipeverythingspn](http://shipeverythingspn.tumblr.com)) fault.
> 
> Gabriel says: This is hufflecas' fault because she decided to write the porn.

 

Everything Sam feels is totally and completely wrong. Castiel is Dean's best friend and Sam practically grew up with the guy. He’s only sixteen, and Cas is two years older than him.

Of course, Sam's body disagrees.

Every time his brother has his best friend over as of late, Sam can find no better course of action than to hide from Castiel, lest either him or Dean catch Sam staring at the beautiful older boy. Today is no exception. Cas has spent the night again. While Sam had successfully avoided him over breakfast by taking his food to his room, Cas is now having a shower in the next room only a few feet away.

Wet.

Naked.

Sam tries to suppress a moan when he hears Cas gasp through the wall. All the walls are thin in their shitty house, so it’s easy to hear Cas in the shower whenever he stays over. Sam is trying his very hardest to keep his mouth shut and his hand away from his dick.

He was doing quite well until Cas decided to vocalize his fantasies.

"Oh fuck," Cas moans. "Deeper!"

Sam lets out a small whimper, dropping his head onto his desk. He knows he should have put in his headphones. But did he? No, of course not. It’s too late to listen to music now. His dick is already half-hard.

"Oh, Sam," Castiel keens.

Sam almost falls off his chair. Did he hear that correctly? He swears he did.

"Fuck Sam, harder," Castiel gasps out.

"Motherfucker!" Sam hisses. If his dick wasn’t completely hard before then it is now. With a burst of courage Sam gets up and swings the door open. He carefully creeps one door down, being careful to watch for Dean, and slips into the bathroom.

Cas must have heard when Sam came in because he’s completely frozen behind the shower curtain.

"Dean?" Cas guesses, his voice unsteady.

"No, it’s Sam." Feeling bold he adds, "I just had to go to the bathroom, I figured you wouldn't mind."

"N-no, not at all," Cas stutters behind the shower curtain. Sam walks over and stands next to the toilet, waiting to see if Cas will continue.

He does.

It’s quiet at first, almost impossible to hear if you weren’t listening for it, but Sam can hear the slick sound of skin on skin. He can even hear Cas' suppressed gasps.

Sam starts to palm himself through his jeans, finally giving in.

That's when Sam hears it: a small gasp and a whispered, "Oh, Sam."

It’s all he can take. He strides over to the shower and throws the curtain open. Cas doesn’t even have time to react before Sam, still fully clothed, has him pressed up against the wall.

"You are one kinky bastard," Sam growls before slamming his lips onto Castiel’s.

Castiel moans loudly into the kiss and shoves his hands into Sam's hair, pulling him closer. The hot spray soaks both their faces. Sam can feel his cock straining against his jeans, which feel even tighter wet. Cas presses the heel of his hand against the wet denim concealing Sam’s erection. Sam no longer tries to contain his loud moan of pleasure. Finally after all these years of crushing on the older boy in secret something is going to come of it.

Or not.

Cas' hands drop from Sam’s crotch, moving to his shoulders to push him back. Sam frowns down at Cas to see a terrified look on his face.

"Sam, are you sure-"

"If you think I don’t want this, you may need to remember how incredibly hard I am." Sam takes one of Cas’s hands and places it back on the bulge in his pants.

Cas whimpers quietly, not properly looking at Sam. He just shakes his head. "Sam, I'm eighteen. You aren't. If... if Dean found out he would have my head on a platter."

Sam scowls at him. "Fuck Dean, and fuck ages. I'm old enough to decide I want you." Sam places a hand gingerly on the side of Castiel’s face.

Cas leans into the touch and sighs. "Sam..."

"It's true." Sam cups Cas’ face in both his hands. “I’ve wanted you for so long, you have no idea.”

“I want you too.”

Sam presses his lips against Castiel’s gently this time. Castiel hesitates only briefly before returning the kiss hungrily, opening his mouth to let Sam in. Sam’s hands fall away from Castiel’s face as he lets them wander over the smooth wet skin of his back, digging his fingernails in just enough to find purchase.

Cas gasps and breaks the kiss. Sam takes the chance to drag his lips over Castiel’s jaw, and down his neck, sucking and teasing the skin with his teeth.

“Sam,” Castiel begins, pulling away slightly.

“What now?” Sam raises his head from Castiel’s neck, his face full of concern.

“...We’ve got to get you out of these clothes. Didn’t anyone tell you that’s how you catch a cold?”

Sam grins. “I don’t think it counts if the water you’re standing under is piping hot.” He places his hands on Cas’s hips and leans in for another kiss. “But I won’t argue with you.” He grabs the hem of his wet cotton t-shirt and peels it up over his chest before tossing it onto the bathroom floor.

Castiel attacks the button on Sam’s jeans, and the zipper in turn. He pulls them down with some difficulty, the wet fabric stiff and heavy. Sam’s boxers stick to the inside of his pants and so both articles come off at once. They make a heavy wet thud as they join the discarded t-shirt on the bathroom floor.

Fully naked, Sam wastes no time pressing his body against Cas, wanting as much skin-on-skin contact as physically possible. Sam locks his gaze with Castiel’s glaringly bright blue eyes, and grazes a thumb across his bottom lip.

“Now, I hate to think that I was interrupting anything.”

Cas doesn’t need to be told twice. Without breaking eye contact he returns his hand to his cock, stroking himself once, twice. Sam leans into him, dipping and rolling his hips so that his own cock slides against Castiel’s length. Cas opens his hand to take both of them, and works his hand up and down both their shafts.

Sam shudders and buries his face in the crook of Cas’s neck. He mouths the sensitive skin there, and cautiously lands a small bite. Cas moans loudly and he sounds as if he’s had the air punched of him. Sam is encouraged and bites down harder, not caring what sort of mark he might leave behind. He steadies himself with his hands against the tiled wall, moving his hips to thrust in and out of Castiel’s hand.

Although younger than him, Sam is taller than Cas and he delights in covering the older boy’s tight muscled frame with his own long one. Steadying himself on his feet Sam’s hands trail over Castiel’s shoulders, his back, and his ass.

Cas releases their cocks from his grip and Sam whines with the loss of contact. Before he can complain too loudly, however, Cas has spun Sam around and is now kissing him against the slick but warm tiles. He’s kissing and sucking in the crook of Sam’s neck, and he’s kissing his way down the smooth chest, over muscles that have yet to completely fill out. Cas eases himself down onto his knees as he drags his teeth ever so slightly over Sam’s hip bones. The taller boy shudders involuntarily. Thank God for non-slip bath mats.  
Sam’s cock is wet from both pre-come and the shower. Cas tongues at the head, teasing, and it draws out a whimper from Sam. Without warning Castiel takes Sam’s entire length in his mouth and it’s almost more than Sam can stand.

“Oh God, Cas!” he cries out, his voice strained. “Fuck, yes.” Cas bobs his head up and down Sam’s length, swirling his tongue around the shaft. Sam buries both his hands in Cas’ hair, harder than he intends to. Cas reacts to the action by sucking Sam down harder, and picks up speed. Sam can’t help it when he thrusts his hips forward. He can feel his cock nudge against the back of Cas’ throat. Cas gags, just a little, and that’s all it takes to send Sam over the edge. Cas pulls off just in time to get a face full of sticky white but he doesn’t seem to mind much. Sam leans his head back against the wall and closes his eyes as he catches his breath.

When he opens his eyes a moment later Cas is standing in front of him, his face still a mess, smiling.

“Heh, sorry about that,” Sam says, as he gently positions Castiel’s face under the stream of water, wiping the last of his come off the older boy’s face.

“It’s quite alright,” Cas replies, his voice still heavy with lust. He stretches up into Sam’s kiss and presses his still-hard cock between Sam’s thighs. Sam squeezes his thighs together gently to give the shorter boy something to thrust into.

“That’s it, Cas,” Sam says, encouraging. “Fuck, you’re so beautiful. Next time I’m going to fuck you so good.” The words tumble out of his mouth before he realizes what he’s saying.

Cas quickens his pace at that, both hands gripping into Sam’s hips so hard he swears there will be marks there tomorrow. It doesn’t take long before Cas’ breath hitches and Sam can feel him spill his hot come against the inside of his thighs. Cas rests his head against Sam’s chest, breathless.

“I’m sorry, Sam,” Cas says.

“What?”

“I’m afraid I’ve used up almost all your hot water,” Cas says haltingly. He reaches down between Sam’s legs and slicks away any sticky strands that remain before extending his hand to the tap and shutting the water off. “Did you… did you mean what you said?”

“About what?”

“About there being a next time.”

Sam takes a deep breath. “Yeah, I do. I mean… if you want.”

“I would like that very much.” Cas presses his forehead against Sam’s chin before angling his face up for a kiss, which Sam returns happily. He licks into Cas’ mouth and suppresses a shiver when he realises he can taste himself on the other boy’s lips. Cas breaks the kiss with a sigh and Sam knows what’s coming next.

“Fuck,” Cas says.

“Yeah, I know.”

“We’re going to have tell Dean, aren’t we?”

 

Sam follows Cas into the living room, hoping for the moment that Dean won’t notice they both have conspicuously wet hair.

“Dean… Sam and I would like to talk to you,” Castiel says.

Dean glances up at them from his book and frowns. “My ‘Doctor Sexy, MD’ addiction is none of your guys’ business. I can stop any time I want to,” Dean retorts defensively.

Castiel tilts his head in confusion while Sam only sighs in annoyance.

Sam knows Dean’s not likely to take this seriously, so he gets right to the point. “Cas and I want to be together,” he spits out quickly.

Dean drops his book.

For a second Sam isn’t sure what he’s going to do. Dean’s face is completely emotionless. Sam isn’t sure he even heard him. That, or he could just be processing the information. Either way, Sam is slightly scared of what his reaction will be.

Then Dean breaks out into a shit eating grin. “It’s about fucking time.”

Sam’s sure that if he weren’t right beside Cas, the older boy would have fallen over from shock. Even Sam has to do a double take at Dean’s reaction.

“Wait, what?” Cas asked, his eyes blinking furiously at his best friend.

Dean crosses his arms in front of his chest. “Well, I’m sorry but I would prefer not being in between you two, watching you guys stare at each other like lovesick teenagers when you think the other isn’t looking. Holy crap, it’s getting annoying.”

Sam furrows his eyebrows together. “So you knew?”

Dean gets up from the couch and stretches his arms above his head. “Yeah well, it’s kind of hard not to notice when your brother and your best friend are madly in love with each other.”

Cas’ lips twitch into a hopeful smile, “… And you don’t care?”

Dean snorts. “Oh hell yeah, I care. You hurt Sammy and I’ll end your life.”

Cas’ smile drops from his face and is replaced with a look of terror.

“But you know, you seem to make Sam pretty happy and Sam makes you happy. I guess that’s what really matters.” Dean smiles at the both of them and walks away, giving Cas a clap on the shoulder before he pauses at the door. “Oh, but, next time you two fuck each other in the shower, please warn a guy.”

“DEAN!”


End file.
